Implementation of motion detection algorithm using acceleration sensors

Size: px

Start display at page:

Download "Implementation of motion detection algorithm using acceleration sensors"

Clarissa York
5 years ago
Views:

1 algorithm using acceleration sensors p.1

2 Table of content Introduction Theoretical Basics Implementation of the algorithm Results and analysis Conclusion p.2

3 Introduction Main Task Develop an motion detection algorithm using Wiimote Motivation Why we want to develop it? Improve real life applications Physiotherapy Home Fitness Gaming p.3

4 Introduction Why Wiimote? Provides acceleration data Easily accessible Cheap and common Original Nintendo Wiimote model Launched November 2006 Gaming remote for Wii Infrared sensor Digital buttons Bluetooth Accelerometer p.4

5 Introduction The accelerometer and Bluetooth are important for our projects Acclereometer inlcudes sensors in xzy direction (Directions illustrated in the picture) Bluetooth module provides connection between Wiimote and host PC p.5

6 Setup Signal processing Computer Wiimote device Matlab p.6

7 Theoretical Basics Fundamental concept this algorithm based on: Cross-Correlation Cross-correlation A mathematical measure of similarity between two independent motions signals Useful to find similar pattern (reference) within another signal (input) p.7

8 Theoretical Basics Working principle Two signals f(t) and g(t) g t shifted with τ and become g(t + τ) Definition of cross correlation is defined as: f g t = f (τ)g t + τ dt The bigger the dot product is, the more similar two signals are. p.5

9 Theoretical Basics The formula from this project J i = R i 2 E i With E i = 1 i+n g 1 rl 2 + r 2 2 l=i l+n R i = i+n g 1 l=i r l r l+n R i :Sum of correlation E i : Sum of energy J i : Correlation matrix r l : Sampled value of reference signal r l+n : Sampled value of input signal p.7

10 Implementation Library for implementation Wiilab J.Brindza and J.Szweda University of Notre Dame Basic steps of motion detection Collecting XYZ acceleration data Store in Matlab Load pattern Using the correlation function Plot result on screen p.8

11 Implementation We have 3 core functions to detect motion: Main, CollectingData, Correlation Main: Where all the created functions will run and setup. CollectingData: It allows to collecting data from the accelerometers and plot it Correlation: The formular of cross correlation is Initialised p.9

12 Implementation Call function Call Function Return result Loop Implementation diagram p.9

13 Result Ideal result Case 1 :Correlation value 1 identical motion Case 2: Correlation value 0 different motion However, this is only ideal Actual result 3 ranges instead of only two states Correlation value < 0.6 different motion Correlation value 0.6 & < 1 similar motion Correlation value 1 identical motion p.10

14 Result Result and analysis Reality motion Analysis motion on Matlab p.11

15 Conclusion Disadvantage: Time delay for processing Loop for plotting makes it slow Perfect motions are specially difficult to make Slow calculation in Matlab How it can be further improved? Optimizing collecting time and sampling rate Optimizing hardware Motion detecting accuracy p.12

16 Thank you for your attention & Question? p.14

17 Live demo p.15

Control Lab. Thermal Plant. Chriss Grimholt

Control Lab. Thermal Plant. Chriss Grimholt Control Lab Thermal Plant Chriss Grimholt Process System Engineering Department of Chemical Engineering Norwegian University of Science and Technology October 3, 23 C. Grimholt (NTNU) Thermal Plant October